A relay technique is standardized in IEEE (Institute of Electrical and Electronics Engineers)802.16j. Further, in 3GPP (3rd Generation Partnership Project) LTE-A (Long Term Evolution-Advanced) also, a technique using a relay node (RN) is studied actively in order to improve the throughput of a user equipment (UE) located at the cell edge.
Further, in LTE, base stations are operated using a frequency band with a bandwidth of 1 MHz to 20 MHz with respect to a certain center frequency. It is thus not assumed that a communication device uses discrete channels. On the other hand, it is under consideration in LTE-A that the user equipment reserves a band of 20 MHz or more by spectrum aggregation that makes simultaneous use of discrete or sequential channels to achieve higher throughput.